This paper reports on an experimental investigation of the effect of different glass types of pyramidal skylight on indoor temperature and indoor illuminance. Four test cells with different glass types of pyramidal skylights were constructed and tested. The volume of each test cell was 1 m3. Different types of glass skylights, clear glass, gray-tinted glass, clear glass covered with green saran and film with transmittance in the visible range of 0.4 adhered to the clear glass were studied. The study reveals that the use of film adhered to the clear glass can dramatically reduce indoor temperature. The maximum indoor illuminance was about 20,000 lx. However, the cost of film is quite high. An alternative way was using clear glass covered with green saran which gives a maximum higher indoor temperature than clear glass cover with film about 3iC and the amount of indoor illuminance was close to the clear glass cover with film. The cost of green saran was very low when compared with the film. Copyright ? (2009) by the International Solar Energy Society.